Removable adhesive tape laminate and separable fastner

ABSTRACT

An adhesive tape construction is removable from one or more objects to which it is adhered and which is reusably separable within its construction so that an object can be separated from another and subsequently reconnected with one another. The adhesive tape construction can be used to bond the other opposed surfaces of objects, including rigid objects such as a picture frame to a wall, where no portion of the adhesive tape construction projects from between the objects, and which subsequently affords easy separation of the objects without damage to either of them. More specifically, the adhesive tape construction includes a stretch release adhesive tape structure combined with a reusable connector surface.

TECHNICAL FIELD

[0001] The present invention relates to adhesive tape structures thatcan be adhered to a surface and thereafter removed without substantiallydamaging the surface or leaving substantial adhesive residue. Moreparticularly, the present invention relates to a removable and separableadhesive tape product.

BACKGROUND OF THE INVENTION

[0002] Many types of adhesive products have been developed which permitthe separable connection of plural objects. For example, laminated tapestructures have been used to bond the opposed surfaces of two objectstogether, such as to bond a wall hanging (e.g. a poster, plaque orpicture) to the surface of a wall.

[0003] In order to permit a separable connection, the adhesive productmay comprise an easily releasable adhesive permitting removal from asubstrate surface while leaving little or no adhesive residue on thesurface. Examples include repositionable products available under thetrade designation “Post-it” from Minnesota Mining and ManufacturingCompany (“3M”) of St. Paul, Minn.

[0004] Another type of removable adhesive tape laminate is asingle-sided or double-sided adhesive tape that is stretchable toaccomplish removal. Such an adhesive tape can have conventionalpressure-sensitive adhesive on one or both major surfaces thereof, and atape backing comprising a highly extensible material. Alternatively, theadhesive may comprise a solid adhesive material that itself provides oneor two adhesive surfaces and is sufficiently extensible. These tapes areoften referred to as stretch release adhesive tapes because when thebacking or solid adhesive layer is stretched after the tape is adheredon one or both sides, the adhesive stretches and undergoes cleaninterfacial debonding from the substrate or substrates to which it isadhered. Moreover, such stretch release adhesive tapes are known to beprovided in strips for bonding objects together and which have a pulltab portion at the end of the strip to facilitate the stretching anddebonding. Examples of such strips and tabs are described in U.S. Pat.Nos. 5,409,189 to Luhmann and 5,516,581 to Kreckel et al, and in U.S.patent application Ser. Nos. 08/308,937 entitled “Removable FoamAdhesive Tape” filed Sep. 20, 1994 and 08/940,555 entitled “RemovableAdhesive Tape with Controlled Sequential Release” filed Sep. 30, 1997,both to Bries et al. An article support specifically designed for usewith such stretch release tapes is disclosed in U.S. Pat. No. 5,507,464to Hamerski et al. An advantage of these stretch release adhesive tapesis that they utilize conventional pressure sensitive adhesives that canprovide a strong bond against shear, peel and lift-off forces. Moreover,heavier weighted objects can be supported.

[0005] With these stretch releasable tape strips, access must beprovided to the tab to permit the release. In the case where the stripis provided between an object support, e.g. a picture hook, and asurface, e.g. a wall, the tab can be provided easily where the supportand exposed tab will be covered by the object (such as a picture) to besupported thereon. Also, with object supports, such as a picture hook,the hook can be reusable by providing a new tape strip. If, however, itis desirable to directly connect an object (such as a picture) to asubstrate (such as a wall) by a stretch releasable strip, the tab needsto extend out from between the opposed surfaces to provide access. Inmany cases, this can provide an objectionable appearance.

[0006] To overcome this problem, a tape laminate structure has beendeveloped having an internally separable layer, which is described inco-pending U.S. patent application Ser. No. 08/746,351 entitled“Internally Separable Tape Laminate” filed Nov. 8, 1996. A tapestructure is provided that can be used to bond together the opposedsurfaces of objects with no portion of the tape structure projectingfrom between the objects and which permits separation of the objects.The tape structure comprises an internally separable layer providedbetween one or two stretch releasable tape strips. By this construction,the objects can be first separated from one another by applying a forcesubstantially perpendicular to the surface direction of the tape laminacausing the internally separable layer to break within itself. That is,a portion of the layer stays attached to one object while anotherportion of the internal layer stays with the other object. Then, withthe objects separated, each layer portion can be removed from itsrespective object by pulling a stretch release tab. Since the stretchrelease tabs are only needed after separation of the internal layer,they can easily be positioned to be hidden when the objects are securedtogether. However, once the objects are separated from another, whichcauses the internal layer to be broken apart, the objects cannot bereconnected with one another unless a new separable tape structure (orother type of product) is used.

[0007] Reusable connectors of many types are also commonly known, withparticular types being more suited for specific different applicationsthan others. Reusable fasteners include mechanical type fasteners, suchas hook and loop systems (e.g. hook and loop products available underthe trade designation “Velcro” and those commercially available underthe trade designation “3M Scotchmate” industrial fastener, fromMinnesota Mining and Manufacturing Company (“3M”) of St. Paul, Minn.),other mechanical interlocking fasteners, such as described in U.S. Pat.No. 5,077,870 to Melbye et al, and intermeshing fasteners (havingconnection without macroscopic mechanical deformation or interference),such as described in U.S. Pat. No. 4,875,259 to Appeldorn.

[0008] Other reusable fasteners include releasable contact responsivefasteners, such as described in PCT International Publication No. WO94/21742 or PCT International Publication No. WO 96/24535. Contactresponsive fasteners include a non-tacky layer and a target layer towhich the non-tacky layer can bond. Contact responsive polymer layersare more readily able to bond to materials having similar solubilityparameters, and when the solubility parameters of the target layer andthe contact responsive polymer layer are sufficiently close, the degreeof interaction between these materials is enhanced and bond formation ispromoted.

[0009] Many reusable fastener systems are also known to be provided withadhesive on their respective non-connector side surfaces for bonding tothe objects which are to be connected. For example, the hook side of ahook and loop system may be adhered to one object while the loop side isadhered to another object. Although these fastener systems permit theseparation of one object from another, each of the objects retains itsportion of the fastener system, which are not easily removable.

SUMMARY OF THE PRESENT INVENTION

[0010] The present invention overcomes the disadvantages andshortcomings of the prior art by providing an adhesive tape constructionthat is removable from one or more objects to which it is adhered andwhich is reusably separable within its construction so that an objectcan be separated from another and subsequently reconnected with oneanother. Thus, the present invention provides an adhesive tapeconstruction that can be used to bond the other opposed surfaces ofobjects, including rigid objects such as a picture frame to a wall,where no portion of the adhesive tape construction projects from betweenthe objects, and which subsequently affords easy separation of theobjects without damage, to either of them. More specifically, theadhesive tape construction includes a stretch release adhesive tapestructure combined with a reusable connector surface.

[0011] The aforementioned advantages are achieved by an adhesive tapefor attaching plural objects to one another, the tape comprising atleast one stretchable backing layer having first and second majorsurfaces and first and second ends, an adhesive surface over at least aportion of the first major surface of the backing layer for bonding to asurface of an object, and a separable connector surface covering atleast a portion of the second major surface of the backing layer. Thebacking layer and adhesive surface may be provided by a single solidadhesive layer or may comprise a separate backing layer combined with anadhesive layer. By this construction, the backing layer and adhesivesurface (provided by separate layers or as a solid adhesive layer actingas both) are stretchable together to effect progressive debonding of theadhesive layer from an object after the adhesive surface is bonded tothat object by the application of a force to the first end of thebacking layer in a direction of extension of the backing layer betweenits first and second ends. Moreover, the separable connector surfacepossesses the ability to be connected, disconnected and reconnected to acooperating connection surface without destruction of the separableconnection surface and/or the adhesive tape.

[0012] Preferably, a second backing layer is also provided having firstand second major surfaces and first and second ends, an adhesive surfaceover at least a portion of its first major surface for bonding to asurface of another object, and a cooperating separable connector surfacecovering at least a portion of the second major surface of the secondbacking layer. The second backing layer and adhesive surface may beprovided by a single solid adhesive layer or may comprise a separatebacking layer combined with an adhesive layer. Again, the second backinglayer and its adhesive surface (provided by separate layers or as asolid adhesive layer acting as both) are stretchable together to effectprogressive debonding of the adhesive surface from the other objectafter its adhesive surface is bonded to that object by the applicationof a force to the first end of the second backing layer in a directionof extension of the second backing layer between its first and secondends and the cooperating separable connector surface possesses theability to be connected, disconnected and reconnected to the connectionsurface of the first backing layer without destruction of the separableconnection surface, the cooperating connection surface and the adhesivetape.

[0013] The separable connection and cooperating separable connectionsurfaces can be provided in any number of different ways depending onthe particular application and the desirable characteristics for thatapplication. Interlocking mechanical connector systems, intermeshingconnector systems, contact responsive fasteners, magnet, and low-tackadhesives are but a few examples of suitable connector systems.

[0014] The present invention is also directed to the combination of theaforementioned tape constructions with a plurality of objects. The tapeconstruction is particularly applicable for the joining of an object toa vertical surface (for example, a picture frame to a wall), but can beused in any number of bonding applications.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 is a perspective view of a general embodiment in accordancewith the present invention of an adhesive tape construction includingtwo stretch release adhesive tape structures combined by a separableconnector;

[0016]FIG. 2 is perspective view illustrating an object attached to awall by the adhesive tape construction of FIG. 1;

[0017]FIG. 3 is an enlarged side view in cross section of the adhesivetape construction of FIG. 1, wherein the stretch release adhesive tapestructures are illustrated connected to one another at the separableconnector system;

[0018]FIG. 4 is an enlarged side view in cross section of the adhesivetape construction of FIG. 1, wherein the stretch release adhesive tapestructures are illustrated separated from one another at the separableconnector system;

[0019]FIG. 5 is an enlarged side view in cross section of a specificembodiment in accordance with the present invention having a hook andloop separable connector system and with the adhesive tape constructionbonded between first and second objects;

[0020]FIG. 6 is an enlarged side view in cross section of the adhesivetape construction of FIG. 5 still adhered to the first and secondobjects but separated from one another and on the hook and loopconnector system;

[0021]FIG. 7 is an enlarged side view in cross section of the adhesivetape construction of FIGS. 5 and 6 showing the tape constructionseparated along the hook and loop connector system and with one of thestretch release adhesive tape structures partially in a debonded statefrom one of the objects;

[0022]FIG. 8 is an enlarged side view in cross section of anotheradhesive tape construction in accordance with the present inventionincluding two stretch release adhesive tape structures connectedtogether by an intermeshing structure connector system and with theadhesive tape construction adhered between first and second objects;

[0023]FIG. 9 is an enlarged side view in cross section of yet anotheradhesive tape construction in accordance with the present inventionincluding a stretch release adhesive tape structure combined with aseparable connector surface wherein the separable connector surface isreusably connected to a first object while the stretch release adhesivetape structure is connected to a second object;

[0024]FIG. 10 is an enlarged view in cross section of yet anotherembodiment of an adhesive tape construction in accordance with thepresent invention having a stretch release adhesive tape structurewherein an adhesive surface of the stretch release adhesive tapestructure provides a reusable separable connector surface adhered to anobject while the adhesive of the stretch release structure is adhered toanother object;

[0025]FIG. 11 is an enlarged side view in cross section of a stretchrelease adhesive tape structure usable in any of the embodiments inaccordance with the present invention having a film/foam/film laminateconstruction; and

[0026]FIG. 12 is an enlarged side view in cross section of yet anotheradhesive tape construction in accordance with the present inventionincluding two stretch release adhesive tape structures, each of theadhesive tape structures sharing a layer of non-tacky adhesive that alsoprovides a separable connector system, and with the adhesive tapeconstruction adhered between first and second objects.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0027] With reference to the Figures, wherein like numerals are used todesignate like components throughout the set of Figures, and initiallyto FIGS. 1 through 4, an adhesive tape construction 10 is illustrated.The adhesive tape 10 comprises a first stretch release adhesive tapestructure 12 and a second stretch release adhesive tape structure 14connected together by a separable connector system 16. Alternatively,one of the first or second stretch release adhesive tape structures maybe replaced with a non-stretch release adhesive, for example, apressure-sensitive adhesive or an epoxy adhesive, in embodiments where amore permanent adhesion on one side of the tape is desired. As shown inFIG. 2, the adhesive tape 10 can be positioned between a first object 50(a wall) and a second object 52 (a picture frame) without any portion ofthe adhesive tape 10 extending out from in between the first and secondobjects 50 and 52. The picture frame is shown connected by a singleadhesive tape 10 positioned to provide a balanced support to the wall;however, any number of adhesive tapes 10 can be used. Moreover, by thepresent invention, the ability to reposition the objects together isfacilitated to allow for accurate alignment and balanced positioning.

[0028] As illustrated best in FIG. 3, the first stretch release adhesivestructure 12 is connected with the second stretch release adhesive tapestructure 14 by the separable connector system 16 and with a first liner18 covering one side of the adhesive tape 10 and a second liner 20covering the other side of the adhesive tape 10. Liners 18 and 20 maycomprise any conventional or developed material, such as a siliconerelease paper, for covering adhesive and which can be easily removed toprovide subsequent bonding of adhesive to an object.

[0029] The first stretch release adhesive structure 12 comprises abacking layer 22 and adhesive layers 24 and 26 of the same or differentpressure-sensitive adhesive compositions on opposite major surfaces ofthe backing layer 22. The thicknesses of the layers of the Figures arenot to scale with respect to one another. Second stretch releaseadhesive structure 14 likewise comprises a backing layer 28 and adhesivelayers 30 and 32 of the same or different pressure-sensitive adhesivecompositions on opposite major surfaces of the backing layer 28. Theexternal surfaces of the adhesive layers 24 and 32 of the first andsecond stretch release adhesive tape structures 12 and 14, respectively,are covered by the liners 18 and 20, respectively.

[0030] The backing layers 22 and 28, as illustrated, comprise astretchable polymeric foam layer. The backing layers 22 and 28 canalternatively comprise a stretchable polymeric film layer. The choice ofpolymeric foam or polymeric film depends on the specific application forthe adhesive tape 10. Polymeric foams can be chosen to optimizeconformability and resiliency properties which are helpful when theadhesive tape 10 is to be adhered to surfaces having surfaceirregularities. Such is the case with a typical wall surface. Polymericfilms may be used instead to increase load bearing strength and rupturestrength of the tapes; however, tapes are more suitable when theapplication is to adhere two very smooth surfaces together. Combinationsof foams and films are contemplated as well, as is further describedbelow. Suitable polymeric foams and films and combinations thereof arediscussed in greater detail below.

[0031] As an alternative to any of the embodiments disclosed orsuggested in this application, solid adhesives can be used instead ofthe combination of a film and/or foam with adhesive layers. Knownstretchable solid adhesives which are generally elastic in nature andusable include rubber-based and acrylate-solid adhesives. When using asolid adhesive as the stretchable backing, it provides not only thebacking layer, but also the two adhesive layers as one. Moreover, asolid adhesive layer may itself comprise plural material provided assublayers or mixtures or otherwise, and may be provided in a way so thatone adhesive surface is the same or different than its other adhesivesurface. For example, two different solid adhesives can be co-extrudedso as to provide a solid adhesive layer comprising two differentsublayers, one forming a first adhesive surface of a first adhesiveaggressiveness and the other forming a second adhesive surface of asecond adhesive aggressiveness. The first may be a strong adhesive,while the second could advantageously be repositionable.

[0032] Furthermore, each of the first and second stretch releaseadhesive tape structures 12 and 14 preferably include a tab 34 and 36,respectively. Tabs 34 and 36 facilitate the stretch release of eachadhesive tape structure 12 and 14, respectively. Tab 34 is preferablyprovided as an extension of the backing layer 12. That is, the backinglayer 22 extends farther longitudinally than the adhesive layers 24 or26. Likewise, the tab 36 comprises an extension of the backing layer 28that extends farther longitudinally than the adhesive layers 30 and 32.Preferably, the adhesive layers 24, 26, 30 and 32 each cover a similararea of the backing layers 22 and 28, respectively. Tabs 34 and 36 canalso be specifically shaped to facilitate the easy gripping thereof forthe stretch release, described below. Where a solid adhesive is used, itmay further be desirable to make the tab(s) non-adhesive. This can bedone by any way of masking the adhesive surface or by rendering theadhesive surface non-adhesive, i.e. detackifying the adhesive surface.

[0033] The separable connector system 16 preferably comprises a firstconnector component 38 and a second connector component 40. As shown inFIG. 3, the first connector component 38 is bonded to the first stretchrelease adhesive tape structure 12 by the surface of adhesive layer 26.Likewise, the second connector component 40 is bonded to the secondstretch release adhesive tape structure 14 by the surface of adhesivelayer 30. Again, the first and second connector components 38 and 40 arepreferably co-extensive with and cover the similar areas as the adhesivelayers 24, 26, 30 and 32.

[0034] The separable connector system 16 can comprise any known ordeveloped reusable connector system for connecting the first and secondstretch release adhesive tape structures 12 and 14 together. It isunderstood that connector systems may have many different propertiesthat make them particularly suitable for certain applications or forconnecting certain types of objects together. Thus, in accordance withthe present invention, any such connector system can be used, but thechosen connector system can be advantageously picked based upon itsproperties that make it particularly suitable for a specific applicationor for connecting certain types of objects together. Preferably, theseparable connector system 16 permits the reusable separation andconnection of the stretch release adhesive tape structures 12 and 14along a general plane. The connector system 16 may comprise, forexample, mechanical type fasteners, including interlocking systems,intermeshing systems (having connection without macroscopic mechanicaldeformation or interference), releasable contact responsive fasteners,and the like, a number of examples of which will be specificallydescribed below. As shown in FIG. 4, the stretch release adhesive tapestructures 12 and 14 are separable so that the first connector component38 remains with the first stretch release adhesive tape structure 12 andthe second connector component 40 remains with the second stretchrelease adhesive tape structure 14 after separation of the connectorsystem 16.

[0035] The area of connection and the type of the separable connectorsystem 16 should be selected so that the force required to separate theadhesive tape 10 into the first and second stretch release adhesive tapestructures 12 and 14 can be readily applied by a user. Such a force maybe applied in a direction substantially perpendicular to the generalplane of the connector system, or as a peeling force, a cleavage force,combinations thereof or other release mechanisms. The type of forceapplied depends largely on the objects that are bonded together. Withvery flexible materials, a peeling force would likely be a primary forceutilized for releasing the separable connector system 16. With rigidmaterials, such as shown in FIG. 2, a cleavage force may be mostlyapplied; that is where a person would pull from the bottom edge of theframe (causing angular displacement) to release the separable connectorsystem 16 of the adhesive tape 10 located at the top. If the frame werepulled to release in a perpendicular direction, a perpendicular force isapplied. Moreover, the connector system 16 should provide sufficientstrength along the general plane of its separation so that, depending onthe specific application, the separable connector system 16 will notseparate based on the use of the adhesive tape 10 between pluralobjects. In the case of an object such as a picture frame mounted to avertical wall surface (as shown in FIG. 2), the connector system 16should be of sufficient strength in the direction of its general planeof separation so that the picture frame will not shift downward duringapplication or over time. The separable connector system 16 provides aninternal static shear strength in a direction parallel to the surfacesof the adhesive layers 24 and 32 for supporting the objects betweenwhich the adhesive tape 10 is attached in that direction. That is, theshear strength of the connector system 16 preferably equals or exceedsthe highest shear force that the pressure sensitive adhesive can developwith surfaces to which it is applied (e.g., about six pounds per squareinch (0.041 MPa)).

[0036] From experimentation when utilizing a primarily perpendicularseparation force (that is without significant other force components,which can change these results dramatically), it has been determinedthat when the adhesive tape 10 is used to attach an object to thesurface of wallpaper or unpainted drywall, the dynamic tensile force ina direction perpendicular to the surfaces of the adhesive layers 24 and32 and the general plane of separation of the connector system 16 shouldbe no more than about 8 to 10 pounds per square inch (0.055 to 0.069MPa) to preclude the possibility of damage to such surfaces. Incontrast, when the adhesive tape 10 is used to attach an object to somepainted surfaces, e.g., the surface of a painted cement block wall, or ametal cabinet with baked on paint, or to the surface of glass or ceramicmaterial, the dynamic tensile force required to separate the separableconnector system 16 can be up to 30, 35 or even 40 pounds per squareinch (0.21, 0.24, or 0.276 MPa) without causing damage to such surfaces.When the adhesive tape 10 is used to attach an object to the surface ofyet other types of materials (e.g., wood or veneer) the dynamic tensileforce in the perpendicular direction required to separate the connectorsystem 16 should be in the range of about 20 to 30 pounds per squareinch (0.14 to 0.21 MPa) to restrict damages to those surfaces.

[0037] When other release mechanisms and forces (e.g. peel or cleavage)are applied, the same concerns are preferably addressed. That is, it isdesirable to provide a requisite separation force without causing damageto one or both of the adhered surfaces. For example, where a peel force,cleave force or combination of forces (including combinations with aperpendicular lift force) is/are to be applied for removal, theseparable connector system 16 may be separated by the application oflower force values.

[0038] In any case, different embodiments of the adhesive tape 10 can bemade with separable connector systems 16 of different types, areas ofconnection, or materials that require different dynamic tensile forcesto separate the connector system 16 as may be appropriate for use of theadhesive tape 10 on different substrates (based on the surfacecomposition or its finish, or the nature of the substrate, e.g. itsflexibility). These different embodiments of the adhesive tape 10 can becoded by making them in different shapes and/or colors to indicate thesubstrates on which their use is most appropriate.

[0039] The aggressiveness of these adhesive layers 24, 26, 30 and 32should be chosen so that the separable connector system 16 comprisingfirst component 38 and second component 40 separates prior to anydelamination of the first or second stretch release adhesive tapestructures 12 or 14 or to separation of the bond between the adhesivelayers 24 and 32 with the surfaces of objects 50 and 52, respectively.As is well known, the adhesive affinity or aggressiveness can bemodified by treatments of the backing materials or surface objects.Treatments include without limitation, for example, corona discharge,plasma discharge, flame treatment, electron beam irradiation,ultraviolet radiation, chemical priming, or acid etching.

[0040] Illustrated in FIG. 5 is a specific example of an adhesive tapeconstruction 110 connected between a first object 50 and a second object52. The first object 50 may be a wall, for example, to which a pictureframe, for example, is attached. The adhesive tape 110 comprises a firststretch release adhesive tape structure 112 and a second stretch releaseadhesive tape structure 114. A separable connector system 116 connectsthe stretch release adhesive tape structures 112 and 114 together asshown in FIG. 5. The first stretch release adhesive tape structure 112comprises a backing layer 122, a first adhesive layer 124 and a secondadhesive layer 126. The second stretch release adhesive tape structure114 comprises backing layer 128, a first adhesive layer 130 and a secondadhesive layer 132. Tabs 134 and 136 are provided as extensions of thebacking layers 122 and 128, respectively, to facilitate stretchremovable objects 50 and 52, in the manner described below.

[0041] In the specific example, a first connector component comprises alayer of hook material 138 which is bonded with the first stretchrelease adhesive tape structure 112 at the surface of the adhesive layer126. A second connector component of the separable connector system 1 16comprises a layer of loop material 140 which is bonded with the secondstretch release adhesive tape structure 114 at the surface of adhesivelayer 130. As shown in FIG. 5, the hook and loop material areinterentangled thereby connecting the separable connector system 116, asconventionally known. Moreover, it is contemplated that any commerciallyavailable hook and loop connector system can be utilized within thisembodiment, so long as the ease of separation can be accomplished inaccordance with a desired force as based on a preferred application andas discussed above. The adhesive layers 124, 126, 130 and 132 preferablycomprise conventional pressure-sensitive adhesive of the same ordifferent types. However, the aggressiveness of these adhesive layersshould be chosen so that the separable connector system 116 comprisinghook material 138 and loop material 140 separates prior to anydelamination of the first or second stretch release adhesive tapestructures I 12 or 1 14 or to separation of the bond between theadhesive layers 124 and 132 with the surfaces of objects 50 and 52,respectively.

[0042] Hook and loop connector systems are but one type of mechanicalinterlocking connector systems which are suggested by this embodiment.By mechanical interlocking, it is meant those fasteners where at leastone of the connector elements undergoes some macroscopic deformation(preferably plastic deformation) so that a mechanical interferenceresults between plural components. Well known examples include hook andloop products commercially available under the trade designation “3MScotchmate” industrial fastener, from Minnesota Mining and ManufacturingCompany (“3M”) of St. Paul, Minn.) and those hook and loop products thatare commercially available under the trade designation “Velcro”. Manyother connector systems and fasteners are know which comprise elementsextending from a generally planar layer of one material to meet withsimilar or dissimilar cooperating members extending from anothergenerally planar layer. Many different modifications of theinterengaging elements are designed based on the requisite force andmanner of separation between the cooperating layers of such a separableconnector system.

[0043] As illustrated in FIG. 6, the first stretch release adhesive tapestructure 112 is separable from the second stretch release adhesive tapestructure 114 by way of the separable connector system 116 withoutchanging substantially the layers making up the first and second stretchrelease adhesive tape structures 112 and 114. A significant advantage ofthe tape constructions in accordance with the present invention is thatbecause the first and second stretch release adhesive tape structuresare separable from one another, no portion or tab or one or both of thestretch release adhesive tape structures need to extend beyond an edgeof either object 50 or 52, as illustrated in FIG. 2. In other words,because the stretch release adhesive tape structures 112 and 114, forexample, are separable from one another, stretch release of one or boththereof can be accomplished after the separation step which providesaccess to-the tabs 134 and 136.

[0044] Additional advantages are based upon the incorporation of aseparable connector system 116 between the first and second stretchrelease adhesive tape structures 112 and 114 because the objects 50 and52 can be separated from one another without destruction of eitherstretch release adhesive tape structure 112 or 114. Moreover, that meansthat the objects 50 and 52 can also be reconnected together by way ofthe same stretch release adhesive tape structures 112 and 114. Furtherin this regard, an advantage of a mechanical interlocking type connectorsystem such as hook and loop material is that not only can the objects50 and 52 be reconnected, they can be positionally adjusted with respectto one another. For example, if object 52 comprises a picture framemounted to a wall 50, the vertical, horizontal or angular position ofthe picture frame 52 can be adjusted relative to the wall 50. Also, oneof the first and second stretch release adhesive tape structures can bedesigned to present an enlarged connector surface as compared to that ofthe other to permit greater flexibility of connection and positioning ofthe objects relative to one another. They can be moved around within thelimits presented by the larger pad. The same can be accomplished byenlarging both pads; however, concern should be given to the force thatmay be required to separate the separable connector system 116 if bothpads are maximally connected.

[0045] Removal of one or both of the stretch release adhesive tapestructures 112 and 114 can be accomplished as illustrated in FIG. 7,wherein the second stretch release adhesive tape structure 114 isillustrated in a partially debonded state. Specifically, a progressivestretch release and removal of the object 52 from the stretch releaseadhesive tape structure 114 is accomplished by the application of aforce F applied as illustrated in FIG. 7 to the tab 136. Force F causesthe stretching of tab 136 and progressively the stretching of thebacking layer 128. Likewise, a progressive debonding of the adhesivelayers 130 and 132 occurs from the surface of the loop material 140 andthe surface of the object 52, respectively. FIG. 7 illustrates theprogressive debonding at an intermediate point of the process. Continuedapplication of force F will cause entire debonding of the second stretchrelease adhesive tape structure 114. Likewise, the first stretch releaseadhesive tape structure 112 can be removed from the surface of object50. That is, by application of a force to the tab 134, the stretchrelease adhesive tape structure 112 is removed from the surface ofobject 50. Thereafter, the surfaces of the objects 50 and 52 aresubstantially clean of adhesive and the hook and loop layers 138 and 140could be reused.

[0046] Another specific embodiment of an adhesive tape construction 210is illustrated in FIG. 8. Again, the tape structure 210, like tapestructure 110, comprises first and second stretch release adhesive tapestructures 212 and 214. Stretch release adhesive tape structure 212comprises a backing layer 222, first adhesive layer 224, and secondadhesive layer 226. The second stretch release adhesive tape structure214 comprises backing layer 228, first adhesive layer 230 and secondadhesive layer 232. Tabs 234 and 236 facilitate removal thereof from therespective surfaces of the objects 50 and 52.

[0047] The first and second stretch release adhesive tape structures 212and 214 are separably connected with one another by way of a separableconnector system 216, which comprises similar intermeshing first andsecond connector components 238 and 240. The first and second connectorcomponents 238 and 240, as illustrated, each comprise a replicated(preferably micro-replicated) surface structure. The surface structureof the first connector component 238 is preferably similar, but need notbe, to the surface structure of the second connector component 240. Thistype of separable connector system relies on the frictionalcharacteristics of the materials and structures making up the first andsecond connector components 238 and 240 without macroscopic deformationand interference between the elements. Examples of this type ofintermeshable connector (including similar and dissimilar matingstructures) are described in U.S. Pat. No. 4,875,259 to Appeldorn, U.S.Pat. No. 5,360,270 to Appeldorn, and U.S. Pat. No. 5,201,101 to Rouseret al, the entire disclosures of which are incorporated herein byreference.

[0048] The ability to separate the first and second stretch releaseadhesive tape structures 212 and 214, and thus the objects 50 and 52,from each other is accomplished in the same way as the above-describedembodiment and preferably takes into concern the same considerations.That is, the intermeshable connector system 216 should permit easyseparation of the objects 50 and 52 depending on the surfaces of theobjects while providing sufficient shear strength and without causingdelamination of either of the stretch release adhesive tape structures212 or 214 themselves or from the surfaces of the objects 50 and 52.After separation, the stretch release adhesive tape structures 212 and214 can advantageously be reconnected to reposition the objects togetherin a same or different position, and if desired, the first and/or secondstretch release adhesive tape structures 212 and 214 can be removed fromthe objects 50 and 52, respectively. Also, one of the first and secondstretch release adhesive tape structures can be designed to present anenlarged connector surface as compared to that of the other to permitgreater flexibility of connection and positioning of the objectsrelative to one another. They can be moved around within the limitspresented by the larger pad. The same can be accomplished by enlargingboth pads; however, concern should be given to the force that may berequired to separate the separable connector system 216 if both pads aremaximally connected. Removal of one or both stretch release adhesivetape structures 212 and 214 is accomplished in the same way as describedabove and illustrated in FIG. 7 wherein a progressive stretching of thebacking layers 222 and 228 causes debonding of the adhesive layers fromthe connector system components 238 and 240 as well as the surfaces ofthe objects 50 and 52.

[0049] Other mechanical connectors can also be used as the separableconnector system 16 as long as the system is separable and preferablyreusable. Other examples include without limitation snaps (plastic ormetal), deformable closure systems, such as those commercially availableunder the trade designation “Ziplok” closures, deformable connectorshaving pins and sockets, and the like. Other closure devices using othermechanisms, such a the creation of suction by a suction cup,electrostatic charge, etc. can be utilized.

[0050] With reference back to FIGS. 1 through 4, other separableconnector systems 16 are specifically contemplated. As a furtherexample, the connector system 16 can comprise a non-tacky adhesivesystem including a contact responsive fastener layer, such as aredisclosed and described in the published PCT application No. WO 96/24535and the published PCT Application No. WO 94/21 742, the entiredisclosures of which are incorporated herein by reference. A contactresponsive fastening layer is a non-tacky layer that has essentially notack to paper, and allows multiple fastening and releasing cycles of thefastening layer with a target surface. The target surface preferably hasa solubility parameter which permits the contact responsive fasteninglayer to have a selectable and consistently repeatable low 90° peelstrength and high shear strength. Preferably, the contact responsivefastener layer can be reused against the target surface many timeswithout noticeable transfer or migration of either material to theother. An advantageous feature of the contact responsive fastener layeris that it is cleanable, for example, with isopropanol or soap andwater, in order to maintain/restore its fastening characteristics.

[0051] Numerous polymeric materials may be used as the contactresponsive layer. The polymeric material may be a homopolymer, a randomcopolymer, a block copolymer, a graft copolymer. It may be crosslinkedor uncrosslinked. Specific examples of polymers useful as the contactresponsive fastening layer include ethylene-containing copolymers,urethane polymers such as urethanes prepared by the reaction of anisocyanate and an isocyanate-reactive compound, acrylic and acrylatepolymers, urethane-acrylate polymers, butyl rubber,butadiene-acrylonitrile polymers and butadiene-acrylonitrile-isoprenepolymers. Blends and mixtures of polymeric materials may be used ifdesired. A preferred polymer for the contact responsive fastener layeris a butadiene-acrylonitrile-isoprene polymer as described in publishedPCT Application No. WO 94/21742, which has been incorporated herein byreference.

[0052] The first connector component 38 may comprise such a contactresponsive fastener material. The second connector component 40 maycomprise a material which provides a target surface to which thecontact's responsive fastener material can releasably and reusablyconnect. Target surfaces are provided as a surface of a layer comprisingthe second connector component 40 in the illustrated embodiment. Asshown, adhesive layers 26 and 30 bond the contact responsive fastenerlayer (first connector component 38) and the target surface materiallayer (second connector component 40) to the first and second stretchrelease adhesive tape structure 12 and 14.

[0053] Target surfaces useful in the present invention may be selectedfrom a wide variety of materials. Useful target surfaces are materialsthat do not bond permanently to the contact responsive fastening layer.Examples of useful target surfaces include those materials previouslyidentified as being useful for the fastening layer, polycarbonate,polyacrylonitrile, butadiene-styrene polymers, poly(methylmethacrylate),polyamide, ethylene vinylacetate copolymer, treated and untreatedpoly(ethylene terephthalate), material available under the tradedesignation “Surlyn,” polystyrene, polyolefins, such as polyethylene,including high density polyethylene, low density polyethylene, linearlow density polyethylene, and linear ultra low density polyethylene,polypropylene, and polybutylenes; vinyl copolymers, and polyvinylacetates, olefinic copolymers, such as ethylene/methacrylate copolymers,ethylene/vinyl acetate copolymers, acrylonitrile-butadiene-styrenecopolymers, and ethylene/propylene copolymers; acrylic polymers andcopolymers; polyurethanes; and combinations of the foregoing. Usefultarget surfaces also include metallic surfaces such as stainless steel;glass; paper; enamel coated substrates; etc. The choice of the targetsurface to be used is dependent upon the needs of the application,provided however, that the target surface and contact responsivefastener layer do no block.

[0054] Alternatively, the target surface can be provided as one of themajor surfaces of one of the layers of either the first and secondstretch release adhesive tape structures 12 and 14, such as a surface ofthe backing layer 28, for example. Then, the first connector component38 comprising the contact responsive fastener material, can berepositionably connected with the target surface of the backing layer28. Again, separation between first and second stretch release adhesivetape structures 12 and 14 is provided. Then, the stretching of eachbacking layer 22 and 28 can remove the first and second stretch releaseadhesive tape structures 12 and 14 from the objects to which they areapplied.

[0055] As shown in FIG. 12, an adhesive tape 610 can comprise first andsecond stretch release adhesive tape structures 612 and 614, whereineach of the first and second stretch release adhesive tape structures612 and 614 comprises a backing layer 622 and 628, respectively, and anadhesive layer 624 and 632, respectively, for bonding between objects 50and 52. A single layer of contact responsive fastener material 638 isbonded between the first and second stretch release adhesive tapestructures 612 and 614 to provide the connector system 616. In this casethe surfaces of backing layers 622 and 628 provide target surfaces towhich the contact responsive fastener layer 638 is bonded. The surfacesmay comprise the same material or different material. If differentmaterials are provided, then the relative adhesion of the bonds betweenthe contact responsive fastener layer 638 and target surfaces of backinglayers 622 and 628 can be varied. Thus, one of the bonds can be theprimary releasable and reusable bond to act as the separable connectorsystem in accordance with the present invention. The other bond can bereleasable or permanent. Moreover, if same materials are used to providethe target surfaces one or both may be treated to alter its adhesion orbonding to the contact responsive fastener layer 638. For example, onetarget surface may be treated by corona discharge. Stretch release ofthe first and second stretch release adhesive tape structures 612 and614 from objects 50 and 52 would be done the same way as describedabove. Separation prior to stretch release is facilitated by therepositionable connection between the contact responsive fastener layerand at least one of the target surfaces.

[0056] Yet another contemplated embodiment comprises the provision ofmagnetic material as the first and second connector components 38 and40. Preferable magnetic materials are those flexible magnetic materialstrips, which are conventionally known. However, rigid magnetic materialcan also be used in accordance with the present invention, depending onthe particular application.

[0057] In particular, the first connector component 38 may comprise alayer of such magnetic strip material and the second connector component40 may comprise a similar magnetic material strip which are arrangedrelative to one another to create an attractive force. As a furtheralternative to this specific embodiment, one of the connector componentlayers 38 or 40 may comprise instead a magnetically attractive materialsuch as a thin sheet of iron or steel or a metal vapor-coated polymericfilm. In the same manner as two magnetic strips, a layer of magneticallyattractive material will be attracted to one magnetic strip. Anadditional advantage of the cooperating magnetic strips or a magneticstrip with magnetically attractive material is that the objects whichare connected together by such a tape construction can be relativelyrepositioned even without separating the first and second stretchrelease adhesive tape structures 12 and 14 from one another. Thecombination of magnetic strips or magnetic strip and magneticallyattractive material will permit relative sliding while maintainingcontact with one another. This is particularly useful for adjusting oraligning the objects to one another. This ability can be enhanced byproviding a larger pad of at least the first or second connectorcomponents 38 or 40 relative to the other.

[0058] As yet another contemplated embodiment, at least one of the firstand second connector components 38 and 40 may comprise a low adhesionmaterial which permits separation and repositioning. The other of thefirst and second connector components 38 and 40 may comprise a materialwhich is easily separable from and reconnectable to such a low adhesionmaterial. Alternatively, both components 38 and 40 may comprise a sameor different low adhesion material if they can be adequately separatedfrom one another. Also, the low adhesion material may be provided as thesecond adhesive layer 26, for example, without the provision of anyspecific connector component 38. One of the major surfaces of thebacking layer 28 can provide the target surface for the low adhesionmaterial instead of a surface of a second connector component 40,although the adhesive layer 30 may be included so long as it permitsseparation with the low adhesion material. One type of low adhesionmaterial suitable for this technique is the low-tack adhesive used inmaking repositionable notes which are commercially available under thetrade designation “Post-it” from Minnesota Mining and Manufacturing ofSt. Paul, Minn. As with any of the above embodiments, one of the firstand second stretch release adhesive tape structures can be designed topresent an enlarged connector surface as compared to that of the otherto permit greater 30 flexibility of connection and positioning of theobjects relative to one another. The components 38 and 40 may also bereplaced with a single layer of material that permits separation fromone or both adhesive layers 26 and 30. For example, well known siliconerelease papers, which are commonly used as adhesive tape liners, can beused in making such a single layer that could be provided between twoadhesive layers. Also, a film can be coated with a low adhesion backingmaterial, as are also well-known (and have been developed to permit theadhesive of a tape to release from the tape backing when in roll form).One or both sides of the single layer may be treated. If only one sideof such a single layer is treated to be releasable, then only oneadhesive layer 26 or 30 would be separable, which functions inaccordance with the present invention. If both sides of such a singlelayer are releasably treated, then both sides can release, although onebond may be more aggressive than the other depending on the adhesives(which may be different), the release treatment to the single layer, orsurface treatments (to either the adhesive or the single layermaterial).

[0059] It is also contemplated that features of the various types ofconnectors can be combined with one another to provide a separableconnector. For example, a magnetic surface or contact responsivefastener surface could also be structured in the manner of anintermeshing connector or may include a low adhesion material layer.

[0060] Illustrated in FIGS. 9 and 10 are further embodiments inaccordance with the present invention where but a single connectorsurface is adequate for connection to a particular object surface. Inthese cases, only a single stretch release adhesive tape structure isthus required. Illustrated in FIG. 9 is a stretch release adhesive tapestructure 312 comprising a backing layer 322, a first adhesive layer 324and a second adhesive layer 326. A tab 334 facilitates removal of thestretch release adhesive tape structure 312. The stretch releaseadhesive tape structure 312 is shown connected between a first object350 and a second object 352. Instead of the provision of a separableconnector system that comprises plural components, a single connectorcomponent 338 is connected to the stretch release adhesive tapestructure 312 at its first adhesive layer 324, as illustrated. Thesecond adhesive layer 326 is shown bonded to the surface of object 352.

[0061] In this case, the surface of the connector component 338 wouldhave a particular affinity or capability to connect with a surface ofobject 350. For example, if the object 350 comprises a magneticallyattractive metal material, the connector component 338 may comprise amagnetic strip such as a flexible magnetic strip, as discussed above.This would permit the objects 350 and 352 to be separated from oneanother and then allow the stretch release adhesive tape strip 12 to beremoved from the surface of the object 352 without having to extend thetab 334 out from between the objects 350 and 352. That is, this singlestretch release structure adhesive tape version includes the sameadvantages as the double stretch release adhesive tape structuresdiscussed above. Once the objects 350 and 352 are separated, access tothe stretch release tab 334 is provided. Another specific example couldbe where the connector component 338 comprises a material such as a hookmaterial (discussed above) and wherein the object 350 includes a surfacethat inherently provides a loop type structure, such as a loose fabricmaterial. If the object 350 provides a surface that is suitable as atarget layer for a contact responsive fastener, as discussed above, theconnector component 338 may simply comprise a contact responsivefastener material. In other words, the object 350 may be a type ofobject which is by its own construction is provided with a surface thatcan act as one of the parts of a connector system, whereby it alreadypossesses a specific capability to cooperate with the material orstructure of a connector component 338.

[0062]FIG. 10 shows a structure similar to FIG. 9 including a stretchrelease adhesive tape structure 412 connecting a first object 450 with asecond object 452 in a separable and removable manner. There is,however, no provision of a separate connector component as in FIG. 9.Instead, the stretch release adhesive tape structure 412 comprises abacking layer 422, a first adhesive layer 424 and a second adhesive 426that comprises a low adhesion material provided directly onto a majorsurface of the backing layer 422. A suitable low-tack adhesive suitablefor this application is again the adhesive used in making repositionablenotes which are commercially available under the trade designation“Post-it” from Minnesota Mining and Manufacturing Company (“3M”) of St.Paul, Minn. This type of application is particularly suitable where anobject 452 comprises a light object such as a sheet of paper which is tobe separable from and potentially repositionable on the surface ofobject 450. When there is no longer a need to present the low-tackadhesive surface of layer 426, or if it otherwise desirable to removethe stretch release adhesive tape structure 412, stretching the tab 434and thus the backing 422 will cause debonding of the adhesive layer 424from the surface of object 450. Again, a separable connection isprovided as well as a removable connection of the adhesive tape from anobject. The tab 434 can remain hidden between the objects 450 and 452because removal of the object 452 facilitates the ability to remove thestretch release adhesive tape structure 412 from the surface of object450.

[0063] With respect to any of the foregoing embodiments specificallydescribed and suggested, the separable connector layer or layers mayalso comprise a stretchable material (elastic or plastic). Then, uponstretch removal of the tape structure, the separable connector componentof that tape structure may be stretched with the backing layer thereof.

[0064] As to any embodiments utilizing a stretchable separable connectorcomponent that is provided as a separate layer, the stretchable separatecomponent layer can be heat laminated or otherwise connected to thebacking layer instead of using adhesive.

[0065] Also as to any of the foregoing embodiments specificallydescribed and suggested, it is contemplated that the backing layer orlayers (if utilized with adhesive layers as opposed to a solid adhesivebacking layer) may be modified to optimize performance for a particularapplication. In general, foams are preferred to add resiliency andcomformability, while films improve load bearing and rupture strength.For components of stretchable backing layers, the combined backing mustbe sufficiently extensible for debonding to occur but of sufficienttensile strength so as not to rupture during debonding. It is alsocontemplated that more layers, (films/foams, etc.) can be provided inany number of ways depending on the application.

[0066]FIG. 11 illustrates a preferred construction of a backing layersuitable for use in any of the above-described backing layers. A foamlayer 500 is illustrated laminated with a first film layer 502 and asecond film layer 504. The external major surfaces of the film layers502 and 504 are coated with adhesive layers 506 and 508 of similar ordifferent adhesive composition. The foam layer 500 and film layers 502and 504 can be laminated together in any number of ways includingco-extrusion, heat lamination, use of adhesives or other conventionalmethods. Preferably, a polyethylene/ethylene/vinyl acetate (EVA)copolymer foam layer is heat laminated with two layers of polyethylenefilm. Such a construction is preferred for its ability to conform tosurfaces while maintaining sufficient rupture strength.

[0067] Suitable materials for any of the stretchable layers described inany of the embodiments above include any materials which are stretchablewithout rupture by at least 50 percent elongation at break and whichhave sufficient tensile strength so as not to rupture before debonding.Again, such stretchable materials may be either elastically deformableor plastically deformable provided sufficient stretching is possible tocause adhesive debonding of both adhesive surfaces for stretch removal.

[0068] Suitable plastic backing materials are disclosed in U.S. Pat.Nos. 5,516,581 and 5,672,402 to Kreckel et al and in co-pending U.S.patent application Ser. No. 08/308,937 (Bries et al.), each of which arecommonly owned by the Assignee of the present application, and thecomplete disclosures of which are hereby incorporated by reference.

[0069] Representative examples of materials suitable for either apolymeric foam or solid polymeric film layer in the backing of the tapeof this invention of the type utilizing a plastic backing includepolyolefins, such as polyethylene, including high density polyethylene,low density polyethylene, linear low density polyethylene, and linearultra low density polyethylene, polypropylene, and polybutylenes; vinylcopolymers, such as polyvinyl chlorides, both plasticized andunplasticized, and polyvinyl acetates; olefinic copolymers, such asethylene/methacrylate copolymers, ethylene/vinyl acetate copolymers,acrylonitrile-butadiene-styrene copolymers, and ethylene/propylenecopolymers; acrylic polymers and copolymers; polyurethanes; andcombinations of the foregoing. Mixtures or blends of any plastic orplastic and elastomeric materials such as polypropylene/polyethylene,polyurethane/polyolefin, polyurethane/polycarbonate,polyurethane/polyester, can also be used.

[0070] Polymeric foam layers for use in the plastic backing of the tapesof the invention generally will have a density of about 2 to about 30pounds per cubic foot (about 32 to about 481 kg/M³), particularly intape constructions where the foam is to be stretched to effectdebonding.

[0071] Preferred for plastic polymeric foam layers in the backing of thetapes of the invention are polyolefin foams. Polymeric foam layers aremost preferably polyolefin foams available under the trade designations“Volextra” and “Volara” from Voltek, Division of Sekisui AmericaCorporation, Lawrence, Mass.

[0072] Elastomeric materials suitable as backings for tapes inaccordance with the present invention include styrene-butadienecopolymer, polychloroprene (neoprene), nitrile rubber, butyl rubber,polysulfide rubber, cis-i,4-polyisoprene, ethylene-propylene terpolymers(EPDM rubber), silicone rubber, polyurethane rubber, polyisobutylene,natural rubber, acrylate rubber, thermoplastic rubbers such as styrenebutadiene block copolymer and styrene-isoprene-styrene block copolymerand TPO rubber materials.

[0073] Solid polymeric film backings are preferably selected frompolyethylene and polypropylene films, with the most preferred materialsbeing unoriented linear low density and ultra low density polyethylenefilms. A preferred polyethylene film is that available under the tradedesignation “Maxilene 200” from Consolidated Thermoplastics Company,Schaumburg, Ill.

[0074] The backing may vary in overall thickness so long as it possessessufficient integrity to be processable and provides the desiredperformance in respect to stretching properties for debonding thebacking or tape from a surface. The specific overall thickness selectedfor a backing will depend upon the physical properties of the polymericfoam layer or layers and any solid polymeric film layer forming thebacking. Where only one polymeric film or foam layer of a multi-layerbacking is intended to be stretched to effect debonding, that layershould exhibit sufficient physical properties and be of a sufficientthickness to achieve that objective.

[0075] A plastic polymeric film layer such as is contained in theconstruction of FIG. 11, preferably will be about 0.4 to 10 mils (0.01mm to 0.25 mm) in thickness, and will most preferably be about 0.4 to 6mils (0.10 mm to 0.15 mm) in thickness.

[0076] The adhesive of the adhesive layers, excluding adhesives usablefor the low-adhesion portion of a differential release tape, cancomprise any pressure-sensitive adhesive, with the particular adhesionproperties being dependent on the use of the tape, with the preferredadhesion properties generally ranging from about 4 N/dm to about 200N/dm, preferably from about 25 N/dm to about 100 N/dm, at a peel angleof 180°, measured according to PSTC-1 and PSTC-3 and ASTM D 903-83 at apeel rate of 12.7 cm/min. Adhesives having higher peel adhesion levelsusually require backings having higher tensile strength.

[0077] Pressure-sensitive adhesives suitable for being made into solidadhesive layers or for application to one side of a separate backingand/or the other in the tapes of the invention include tackified rubberadhesives, such as natural rubber; olefins; silicones, such as siliconepolyureas; synthetic rubber adhesives such as polyisoprene,polybutadiene, and styrene-isoprene-styrene,styrene-ethylene-butylene-styrene and styrene-butadiene-styrene blockcopolymers, and other synthetic elastomers; and tackified or untackifiedacrylic adhesives such as copolymers of isooctylacrylate and acrylicacid, which can be polymerized by radiation, solution, suspension, oremulsion techniques. Preferred are synthetic rubber adhesives oracrylics.

[0078] The thickness of each adhesive layer can range from about 0.6mils to about 40 mils (about 0.015 mm to about 1.0 mm), preferably fromabout 1 mils to about 16 mils (about 0.025 mm to about 0.41 mm). In thispreferred range of thicknesses, the thicker layers tend to cause thetapes to be more easily removable than do thinner layers. This is incontrast to conventional methods of removal, such as removal by peelingat peel angles of 90° or higher. In general, thicker layers of adhesivetend to cause the tapes to exhibit higher peel strength at a peel angleof 180° than do thinner layers. When the tapes of the present inventionare released by stretching at a low angle, i.e., under 35°, the adhesivetends to be constrained by the backing and substrate for a single-coatedadhesive tape and by the backing and two substrates for a double-coatedadhesive tape, and is forced to undergo significant elongation. Underthese conditions, the adhesive layer (or each adhesive layer) contracts,which reduces its cross-sectional area. Since the cross-sectional area,i.e., thickness times width, of a thinner layer of adhesive is alreadyless than that of a thicker layer of adhesive, stress, i.e., force perunit area, is greater in the thinner layer of adhesive than in thethicker layer of adhesive. This leads, in effect, to a stiffening of theadhesive. Because stiffer layers offer more resistance to deformation,the force required for debonding is greater. The exposed adhesive layeror layers may be laminated to a conventional release liner prior to use.

[0079] Adhesives for adhering one polymeric foam layer to either anotherpolymeric foam layer or a solid polymeric film layer include thosepressure-sensitive adhesive compositions described above. Preferably theadhesive layer for adjoining one polymeric layer of the backing toanother will be about 1 to 10 mils (about 0.025 to 0.25 mm) inthickness. Other methods of adhering the polymeric layers of the backingto one another include such conventional methods as co-extrusion or heatwelding.

[0080] The tape of this invention can be produced by any conventionalmethod for preparing pressure-sensitive adhesive tapes. For example, theadhesive can either be directly coated onto the backing, or it can beformed as a separate layer and then later laminated to the backing.

[0081] Removing the tape from the surface of a substrate can be carriedout by simply stretching the tape in a direction up to an angle of about35° from the surface. Preferably, the tape can be removed from thesurface of a substrate by stretching the tape at an angle of no greaterthan about 10°. Removal at the appropriate angle will result in leavingno substantial or appreciable adhesive residue and in preventing thesurface of the substrate from being damaged.

[0082] Debonding of a highly elongated adhesive tape of this inventionat low angles is characterized by a “sharp” type of crack propagation.Like fracture of glassy materials, a sharp crack leads to high stressconcentration at the crack front, where there is a low volume ofadhesive material (in which stress may be dissipated). High stressconcentration at the crack front leads to what is called brittlecleavage failure of the adhesive. Such failure typically occurs with lowforce (because of the low amount of energy dissipated in the adhesivematerial) and is cleanly interfacial.

[0083] In contrast, for higher peeling angles, i.e., angles generallygreater than 35°, the backing tends not to stretch and the adhesivetends to undergo filamentation and rupture cohesively. Like fracture ofglassy materials, propagation of a “blunt” crack is preceded by crazing.In this model, the observed filamentation of the adhesive at higherangles serves principally as an energy dissipation mechanism, analogousto craze fibrils found in glassy materials. The greater the energydissipation, the greater the resistance to peeling and the higher theforce required to peel the tape. A larger volume of material is involvedin energy dissipation, and, as stated previously, stress is lessconcentrated. The adhesive filaments rupture cohesively to leave residueof adhesive on the surface or to cause damage to the surface.

[0084] The tape of this invention can be-use-d in several areas,including the following categories:

[0085] (1) mounting applications on surfaces such as painted wallboard,plaster, concrete, glass, metal or plastic, such as wall hangings,dispensers, wire clips, body side molding on vehicles, carrying handles,signing application, e.g., road signs, vehicle markings, transportationmarkings, and reflective sheetings, etc.;

[0086] (2) joining or assembly applications;

[0087] (3) cushioning or sound deadening applications, such ascushioning materials for placement beneath objects or sound insulativesheet materials;

[0088] (4) closure applications, such as container closures, e.g., boxclosures, closures for food and beverage containers, and the like;diaper closures; surgical drape closures, and the like; and

[0089] (5) removable labels, such as price tags or identification labelson containers.

[0090] The particular construction of the tape, e.g., the type ofbacking, the type of adhesive compositions, and relative position ofbacking and adhesive layers, are often required to be different for eachcategory of use.

1. An adhesive tape for attaching plural objects to one another, saidtape comprising a stretchable backing layer having first and secondmajor surfaces and first and second ends, a non-adhesive manuallyengageable tab portion at one of said first and second ends tofacilitate stretching of said backing layer, a first adhesive surfaceover at least a portion of said first major surface of said backinglayer for bonding to a surface of an object, a second adhesive surfaceover at least a portion of the second major surface of said backinglayer, the second adhesive surface over the second major surface of saidbacking layer is directly bonded to a separable connector layer, and aseparable connector surface is provided as a surface of said separableconnector layer, said separable connector surface covering at least aportion of said second major surface of said backing layer, wherein saidbacking layer and said first adhesive surface are stretchable togetherto effect progressive debonding of the first adhesive surface from anobject, after the adhesive surface is bonded to that object, by theapplication of a force to the first end of the backing layer in adirection of extension of the backing layer between its first and secondends, and said separable connector surface possesses the ability to beconnected, disconnected and reconnected to a cooperating connectionsurface without destruction of the separable connector surface and theadhesive tape.
 2. The adhesive tape of claim 1, wherein said separableconnector layer and surface comprise a layer of an interlockingconnector material.
 3. The adhesive tape of claim 1, wherein saidseparable connector layer and surface comprise a layer of anintermeshing material.
 4. The adhesive tape of claim 1, wherein saidseparable connector layer and surface comprise a layer of loop or hookfasteners.
 5. The adhesive tape of claim 1, further comprising astretchable second backing layer having first and second major surfacesand first and second ends, an adhesive surface over at least a portionof said first major surface of said second backing layer for bonding toa surface of another object, and a cooperating separable connectorsurface covering at least a portion of said second major surface of saidsecond backing layer, wherein said second backing layer and its adhesivesurface are stretchable together to effect progressive debonding of theadhesive surface from the other object, after its adhesive surface isbonded to that object, by the application of a force to the first end ofthe second backing layer in a direction of extension of the secondbacking layer between its first and second ends and said cooperatingseparable connector surface possesses the ability to be connected,disconnected and reconnected to said connection surface of said firstbacking layer without destruction of the separable connection surface,the cooperating connection surface and the adhesive tape.
 6. Theadhesive tape of claim 5, further comprising a second adhesive surfaceover at least a portion of the second major surface of said secondbacking layer.
 7. The adhesive tape of claim 6, wherein said secondadhesive surface of the second major surface of the second backing layercomprises a low-tack adhesive, and said cooperating separable connectorsurface comprises a surface of the low-tack adhesive that can reusablyadhere to said separable connector surface of said first backing layer.8. The adhesive tape of claim 6, wherein the second adhesive surface ofthe second major surface of the second backing layer is bonded to acooperating separable connector layer, and said cooperating separableconnector surface is provided as a surface of said cooperating separableconnector layer.
 9. The adhesive tape of claim 8, wherein said separableconnector layer and surface comprise a strip of magnetic material, andsaid cooperating separable connector layer and surface comprise a stripof magnetic material.
 10. The adhesive tape of claim 8, wherein saidseparable connector layer and surface comprise a strip of magneticmaterial, and said cooperating separable connector layer and surfacecomprise a layer of magnetically attractive material.
 11. The adhesivetape of claim 8, wherein said separable connector layer and surfacecomprise a layer of an interlocking connector material, and saidcooperating separable connector layer and surface comprise interlockingconnector material.
 12. The adhesive tape of claim 11, wherein saidinterlocking connector material comprises hook and loop connector means.13. The adhesive tape of claim 8, wherein said separable connector layerand surface comprise a layer of an intermeshing material, and saidcooperating separable connector layer and surface comprise similarintermeshing material.
 14. The adhesive tape of claim 8, wherein saidseparable connector layer and surface comprise a layer of a contactresponsive material, and said cooperating separable connector layer andsurface comprise a material providing a target surface for said contactresponsive material.
 15. The adhesive tape of claim 5, wherein theadhesive surfaces over at least portions of the first and second majorsurfaces of said first and second backing layers are provided byadhesive layers that cover at least portions of the first and secondmajor surfaces of said first and second backing layers, and said firstand second backing layers comprise polymeric material.
 16. The adhesivetape of claim 5, wherein the adhesive surfaces over at least portions ofthe first and second major surfaces of said first and second backinglayers and said first and second backing layers themselves are providedby a solid adhesive layer.
 17. A stretch releasing adhesive tape with arefastenable connection for attaching plural objects to one another,comprising: (a) a stretchable backing layer having first and secondmajor surfaces and first and second ends, said first end including anon-adhesive manually engageable tab portion to facilitate stretching ofsaid backing layer, said backing layer having a lengthwise elongation atbreak of from about 50% to about 1200%, said backing layer including afirst adhesive layer over at least a portion of said first major surfacefor bonding to a surface of an object, a second adhesive layer over atleast a portion of said second major surface of said backing layer, thesecond adhesive layer over the second major surface of said backinglayer is directly bonded to a separable connector layer; and (b) aseparable connector surface is provided as a surface of said separableconnector layer, said separable connector surface distributed over atleast a portion of said second major surface of said backing layer, saidseparable connector surface possessing the ability to be connected,disconnected, and reconnected to a cooperating connection surfacewithout destruction of the separable connector surface and the adhesivetape; wherein said backing layer and said first adhesive layer arestretchable together to effect progressive debonding of the firstadhesive layer from an object, after the first adhesive layer is bondedto that object, by the application of a force to the manually engageabletab portion in a direction of extension.
 18. A stretch releasingadhesive tape with a refastenable connection for attaching pluralobjects to one another, comprising: (a) a stretchable backing layerhaving first and second major surfaces and first and second ends, saidfirst end including a non-adhesive manually engageable tab portion tofacilitate stretching of said backing layer, said backing layer having alengthwise elongation at break of from about 50% to about 1200%, saidbacking layer including an adhesive surface over at least a portion ofsaid first major surface for bonding to a surface of an object, saidbacking layer and said adhesive surface comprising a solid layer ofpressure sensitive adhesive, at least a portion of said second majorsurface of said backing layer is directly bonded to a separableconnector layer; and (b) a separable connector surface is provided as asurface of said separable connector layer, said separable connectorsurface possessing the ability to be connected, disconnected, andreconnected to a cooperating connection surface without destruction ofthe separable connector surface and the adhesive tape; wherein saidbacking layer and said adhesive surface are stretchable together toeffect progressive debonding of the adhesive surface from an object,after the adhesive surface is bonded to that object, by the applicationof a force to the manually engageable tab portion in a direction ofextension.
 19. An adhesive tape for attaching plural objects to oneanother, said tape comprising a stretchable backing layer having firstand second major surfaces and first and second ends, a non-adhesivemanually engageable tab portion at one of said first and second ends tofacilitate stretching of said backing layer, an adhesive surface over atleast a portion of said first major surface of said backing layer forbonding to a surface of an object, and a separable connector layer isdirectly bonded to at least a portion of said second major surface ofsaid backing layer, a separable connector surface comprising a surfaceof low-tack adhesive provided as a surface of said separable connectorlayer, wherein said backing layer and said adhesive surface arestretchable together to effect progressive debonding of the adhesivesurface from an object, after the adhesive surface is bonded to thatobject, by the application of a force to the first end of the backinglayer in a direction of extension of the first and second ends, and saidseparable connector surface possesses the ability to be connected,disconnected and reconnected to a cooperating connection surface withoutdestruction of the separable connector surface and the adhesive tape.20. An adhesive tape for attaching plural objects to one another, saidtape comprising a stretchable backing layer having first and secondmajor surfaces and first and second ends, a non-adhesive manuallyengageable tab portion at one of said first and second ends tofacilitate stretching of said backing layer, a first adhesive surfaceover at least a portion of said first major surface of said backinglayer for bonding to a surface of an object, a second adhesive surfaceover at least a portion of the second major surface of said backinglayer, the second adhesive surface over the second major surface of saidbacking layer is adhesively bonded to a separable connector layer, and aseparable connector surface comprising hook or loop fasteners isprovided as a surface of said separable connector layer, said separableconnector surface covering at least a portion of said second majorsurface of said backing layer, wherein said backing layer and said firstadhesive surface are stretchable together to effect progressivedebonding of the first adhesive surface from an object, after theadhesive surface is bonded to that object, by the application of a forceto the first end of the backing layer in a direction of extension of thebacking layer between its first and second ends, and said separableconnector surface possesses the ability to be connected, disconnectedand reconnected to a cooperating connection surface without destructionof the separable connector surface and the adhesive tape.
 21. A stretchreleasing adhesive tape with a refastenable connection for attachingplural objects to one another, comprising: (a) a stretchable backinglayer having first and second major surfaces and first and second ends,said first end including a non-adhesive manually engageable tab portionto facilitate stretching of said backing layer, said backing layerhaving a lengthwise elongation at break of from about 50% to about1200%, said backing layer including a first adhesive layer over at leasta portion of said first major surface for bonding to a surface of anobject, a second adhesive layer over at least a portion of said secondmajor surface of said backing layer, the second adhesive layer over thesecond major surface of said backing layer is adhesively bonded to aseparable connector layer; and (b) a separable connector surfacecomprising hook or loop fasteners is provided as a surface of saidseparable connector layer, said separable connector surface distributedover at least a portion of said second major surface of said backinglayer, said separable connector surface possessing the ability to beconnected, disconnected, and reconnected to a cooperating connectionsurface without destruction of the separable connector surface and theadhesive tape; wherein said backing layer and said first adhesive layerare stretchable together to effect progressive debonding of the firstadhesive layer from an object, after the first adhesive layer is bondedto that object, by the application of a force to the manually engageabletab portion in a direction of extension.
 22. A stretch releasingadhesive tape with a refastenable connection for attaching pluralobjects to one another, comprising: (a) a stretchable backing layerhaving first and second major surfaces and first and second ends, saidfirst end including a non-adhesive manually engageable tab portion tofacilitate stretching of said backing layer, said backing layer having alengthwise elongation at break of from about 50% to about 1200%, saidbacking layer including an adhesive surface over at least a portion ofsaid first major surface for bonding to a surface of an object, saidbacking layer and said adhesive surface comprising a solid layer ofpressure sensitive adhesive; and (b) a separable connector surfacecomprising hook or loop fasteners distributed over at least a portion ofsaid second major surface of said backing layer, said separableconnector surface possessing the ability to be connected, disconnected,and reconnected to a cooperating connection surface without destructionof the separable connector surface and the adhesive tape; wherein saidbacking layer and said adhesive surface are stretchable together toeffect progressive debonding of the adhesive surface from an object,after the adhesive surface is bonded to that object, by the applicationof a force to the manually engageable tab portion in a direction ofextension.
 23. An adhesive tape for attaching plural objects to oneanother, said tape comprising a stretchable backing layer having firstand second major surfaces and first and second ends, a non-adhesivemanually engageable tab portion at one of said first and second ends tofacilitate stretching of said backing layer, an adhesive surface over atleast a portion of said first major surface of said backing layer forbonding to a surface of an object, and a separable connector surfacecomprising a surface of low-tack adhesive covering at least a portion ofsaid second major surface of said backing layer, wherein said backinglayer and said adhesive surface are stretchable together to effectprogressive debonding of the adhesive surface from an object, after theadhesive surface is bonded to that object, by the application of a forceto the first end of the backing layer in a direction of extension of thefirst and second ends, and said separable connector surface possessesthe ability to be connected, disconnected and reconnected to acooperating connection surface without destruction of the separableconnector surface and the adhesive tape.
 24. An adhesive tape forattaching plural objects to one another, said tape comprising astretchable backing layer having first and second major surfaces andfirst and second ends, a non-adhesive manually engageable tab portion atone of said first and second ends to facilitate stretching of saidbacking layer, a first adhesive surface over at least a portion of saidfirst major surface of said backing layer for bonding to a surface of anobject, a second adhesive surface over at least a portion of the secondmajor surface of said backing layer, the second adhesive surface overthe second major surface of said backing layer is adhesively bonded to aseparable connector layer, and a separable connector surface comprisinga strip of magnetic material is provided as a surface of said separableconnector layer, said separable connector surface covering at least aportion of said second major surface of said backing layer, wherein saidbacking layer and said first adhesive surface are stretchable togetherto effect progressive debonding of the first adhesive surface from anobject, after the first adhesive surface is bonded to that object, bythe application of a force to the first end of the backing layer in adirection of extension of the backing layer between its first and secondends, and said separable connector surface possesses the ability to beconnected, disconnected and reconnected to a cooperating connectionsurface without destruction of the separable connector surface and theadhesive tape.
 25. An adhesive tape for attaching plural objects to oneanother, said tape comprising a stretchable backing layer having firstand second major surfaces and first and second ends, a non-adhesivemanually engageable tab portion at one of said first and second ends tofacilitate stretching of said backing layer, a first adhesive surfaceover at least a portion of said first major surface of said backinglayer for bonding to a surface of an object, a second adhesive surfaceover at least a portion of the second major surface of said backinglayer, the second adhesive surface over the second major surface of saidbacking layer is adhesively bonded to a separable connector layer, and aseparable connector surface comprising a layer of contact responsivematerial is provided as a surface of said separable connector layer,said separable connector surface covering at least a portion of saidsecond major surface of said backing layer, wherein said backing layerand said first adhesive surface are stretchable together to effectprogressive debonding of the first adhesive surface from an object,after the first adhesive surface is bonded to that object, by theapplication of a force to the first end of the backing layer in adirection of extension of the backing layer between its first and secondends and said separable connector surface possesses the ability to beconnected, disconnected and reconnected to a cooperating connectionsurface without destruction of the separable connector surface and theadhesive tape.